👉 Coulomb is a unit of electric charge. It's named after the French physicist Charles-Augustin de Coulomb, who introduced it to define the relationship between charges and voltages in 1826. The coulomb (symbol: C) is equivalent to one joule per coulomb of charge. Coulomb has many important applications in physics and chemistry. It's used in determining the strength of electric fields between charged objects, calculating the voltage across a circuit, measuring